CORROSION RESISTANCE OF LASER WELDED 13CR STAINLESS STEEL WITH POST WELD HEAT TREATMENTS PIPE

摘要

Corrosion properties in laser welded low carbon 13Cr martensitic stainless steel pipe have been studied in terms of its microstructural features. Optical microstructure in the laser weld metal showed a fine martensitic phase after quenching and tempering heat treatments. Hardness distributed homogeneously across the laser weld metal. No segregation was observed around the laser weld metal by Electron Probe Micro Analysis (EPMA). Uniform distributions of anti corrosive elements such as Cr and Mo were observed by Transmission Electron Microscope (TEM) within the laser weld metal. The microstructural homogeneity in the laser weld metal due to its rapid cooling rate, ensured the excellent corrosion resistance to CO_2 corrosion, sulfide stress cracking and hydrogen embrittlement under cathodic protection.